• Journal of the Economic Geographical Society of Korea
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• v.19 no.1
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• pp.18-32
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• 2016

In the Hyper-connected society, each country set up its own policy and central government as well as provincial government makes a basic plan of developing IoT. Gyeonggi provincial government needs to cope actively with the changing international and national circumstances. The purpose of this paper is to frame policy as a provincial government with analysis IoT industry-academia-institute-governments ecosystem and in-depth interview. There are IoT related SMEs in Gyeonggi, especially manufacturing business and device fields. Universities are doing IoT researches by R&D funds from central as well as provincial governments. Central government-affiliated Institutions are researching. It is necessary for Gyeonggi provincial government to establish policy in order to actively operate IoT ecosystem while each innovation actors are cooperated in doing IoT; system/governce maintenance, environments and test-bed for the application.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.231-238
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• 2013

This paper describes a DC-DC converter IC for Flat Panel Displays. In case of operate LCD devices various type of DC supply voltage is needed. This device can convert DC voltage from 6~14[V] single supply to -5[V], 15[V], 23[V], and 3.3[V] DC supplies. In order to meet current and voltage specification considered different type of DC-DC converter circuits. In this work a negative charge pump DC-DC converter(-5V), a positive charge pump DC-DC converter(15V), a switching Type Boost DC-DC converter(23V) and a buck DC-DC converter(3.3V). And a oscillator, a thermal shut down circuit, level shift circuits, a bandgap reference circuits are designed. This device has been designed in a 0.35[${\mu}m$] triple-well, double poly, double metal 30[V] CMOS process. The designed circuit is simulated and this one chip product could be applicable for flat panel displays.

• Polymer(Korea)
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• v.27 no.3
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• pp.183-188
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• 2003

The dielectric constants of fluorine-containing epoxy resins, 2-diglycidylether of benzotrifluoride(FER)/4,4'-diamino-diphenyl methane (DDM) and diglycidylether of bisphenol-A (DGEBA)/DDM systems were evaluated by dielectric spectrometer. Glass transition temperature and thermal stability factors, including initial decomposed temperature, temperatures of maximum rate of degradation, and decomposition activation energy of the cured specimens were investigated by dynamic mechanical analysis and thermogravimetric analysis. For the mechanical properties of the casting specimens, the fracture toughness, flexural, and impact tests were performed, and their fractured surfaces were examined by scanning electron microscope. The dielectric constant of FER/DDM system was lower than that of commercial DGEBA/DDM system, and the mechanical properties of the cured specimens showed higher values than those of DGEBA/DDM system. This was probably due to the introduction of trifluoromethyl (CF$_3$) group into the side chain of the epoxy resins, resulting in improving the electric and mechanical properties of the epoxy cure system studied.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.177-193
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• 2011

This study constructed an ontology targeting journal articles and evaluated its performance. Also, the performance of a triple structure ontology was compared with the knowledge base of an inverted index file designed for a simple keyword search engine. The coverage was three years of articles published in the Journal of the Korean Society for Information Management from 2007 to 2009. Protege was used to construct an ontology, whilst utilizing an inverted index file to compare performance. The concept ontology was manually established, and the bibliography ontology was automatically constructed to produce an OWL concept ontology and an OWL bibliography ontology, respectively. This study compared the performance of the knowledge base of the ontology, using the Jena search engine with the performance of an inverted index file using the Lucene search engine. As a result, The Lucene showed higher precision rate, but Jena showed higher recall rate.

• Journal of KIISE
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• v.44 no.4
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• pp.383-391
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• 2017

As we enter a new era of Big Data, the amount of semantic data has rapidly increased. In order to derive meaningful information from this large semantic data, studies that utilize the SWRL(Semantic Web Rule Language) are being actively conducted. SWRL rules are based on data extracted from a user's empirical knowledge. However, conventional reasoning systems developed on single machines cannot process large scale data. Similarly, multi-node based reasoning systems have performance degradation problems due to network shuffling. Therefore, this paper overcomes the limitations of existing systems and proposes more efficient distributed inference methods. It also introduces data partitioning strategies to minimize network shuffling. In addition, it describes a method for optimizing the incremental reasoning process through data selection and determining the rule order. In order to evaluate the proposed methods, the experiments were conducted using WiseKB consisting of 200 million triples with 83 user defined rules and the overall reasoning task was completed in 32.7 minutes. Also, the experiment results using LUBM bench datasets showed that our approach could perform reasoning twice as fast as MapReduce based reasoning systems.

• Journal of KIISE:Databases
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• v.34 no.6
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• pp.518-527
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• 2007

It is an important issue to find out the difference between RDF documents, because RDF documents are changed frequently. When RDF documents contain blank nodes, we need a matching technique for blank nodes in the change detection. Blank nodes have a nested form and they are used in most RDF documents. A RDF document can be modeled as a graph and it will contain many subtrees. We can consider a change detection problem as a minimum cost tree matching problem. In this paper, we propose a change detection technique for RDF documents using the labeling scheme for blank nodes. We also propose a method for improving the efficiency of general triple matching, which used predicate grouping and partitioning. In experiments, we showed that our approach was more accurate and faster than the previous approaches.

• Journal of KIISE:Databases
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• v.35 no.2
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• pp.112-124
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• 2008

RDF and OWL are the primary base technologies for implementing Semantic Web. Recently, many researches related with them, or applying them into the other application domains, have been introduced. However, relatively little work has been done for securing the RDF and OWL data. In this article, we briefly introduce an RDF triple based model for specifying RDF access authorization related with RDF security. Next, to efficiently find the authorization conflict by RDF inference, we introduce a method using prime number graph labeling in detail. The problem of authorization conflict by RDF inference is that although the lower concept is permitted to be accessed, it can be inaccessible due to the disapproval for the upper concept. Because by the RDF inference, the lower concept can be interpreted into the upper concept. Some experimental results show that the proposed method using the prime number graph labeling has better performance than the existing simple method for the detection of the authorization conflict.

• Journal of KIISE
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• v.45 no.2
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• pp.134-140
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• 2018

A chat system is a computer program that understands user's miscellaneous utterances and generates appropriate responses. Sometimes a chat system needs to answer users' simple information-seeking questions. However, previous generative chat systems do not consider how to embed knowledge entities (i.e., subjects and objects in triple knowledge), essential elements for question-answering. The previous chat models have a disadvantage that they generate same responses although knowledge entities in users' utterances are changed. To alleviate this problem, we propose a knowledge entity embedding method for improving question-answering accuracies of a generative chat system. The proposed method uses a Siamese recurrent neural network for embedding knowledge entities and their synonyms. For experiments, we implemented a sequence-to-sequence model in which subjects and predicates are encoded and objects are decoded. The proposed embedding method showed 12.48% higher accuracies than the conventional embedding method based on a convolutional neural network.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.295-304
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• 2011

To effectively manage research information in the field of national defense, metadata about the information should be managed systematically, and an integrated system to help convergence and management of the information should be implemented based on the metadata. In addition, the system should provide the users with effective integrated search services in a mobile environment, because searching via the use of mobile devices is increasing. The objective of this paper is to suggest a MSISS (Mobile Semantic Integrated Search System), which satisfies the requirements for effective management of the national defense research information. Specifically, we defined national defense research ontologies and national defense research rules after analyzing the Dublin Core metadata and database information of the major military research institutions. We implemented a prototype system for MSISS to demonstrate the use of the ontologies and rules for semantic integrated searching of the military research information. We also presented a triple-based search service to support semantic integrated search in a mobile environment and suggested future mobile semantic integrated search services.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.72-72
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• 2011

산업의 발달과 건설재료의 개발 및 설계 시공 기술의 급속한 발전으로 더 가볍고 더 긴 경간을 가진 교량이 건설되고 있다. 그러나 교량이 더 길어지고 가벼워질수록 풍하중에 의한 영향은 더욱 크게 받게 되어 여러 종류의 피해를 입게 된다. 이제는 어느 정도 잘 알려진 1940년에 발생한 Tacoma Narrow교의 붕괴사고는 내풍 설계의 필요성을 극단적으로 보여주는 대표적인 예로서 본격적인 내풍 공학 연구에 시발점이 되었다. 현재까지 아직 시공은 되지 않았으나 기본 설계 및 내풍안정성 평가가 완료되 주경간장 3,300m의 Messina교 및 2,800m의 일본해협횡단도로 프로젝트 초장대 현수교(안)의 출현까지 짧은 기간 동안 비약적인 기술 성장을 이루고 있다. 장대교량의 설계시 많은 풍동실험을 거쳐서 내풍안정성이 뛰어난 단면을 찾게 된다. Akashi교의 경우에도 트러스, 싱글박스, 트윈박스 등의 다양한 단면에 대한 풍동실험을 수행한 끝에 최종적으로 트러스 단면을 선택하였다. Great Belt교에서는 싱글박스 단면을 대상으로 다양한 단부 각도에 대한 결과를 바탕으로 최종 단면을 선정하였다. Stonecutter 교에는 트윈박스를 채용하여 기존 싱글박스를 뛰어넘는 도약을 단행하였다. 그리고 Messina교의 경우에는 약 20년에 걸쳐서 설계를 진행해 오면서 점진적으로 단면을 개선하여 최종적으로 트리플박스 단면을 채택하였다. 국내에서도 광양대교의 설계시 싱글박스에서 시작하여 트윈박스의 간격 최적화를 통하여 최종단면을 도출하였다. Akashi교는 최장경간장을 자랑하지만 고전적인 트러스 단면을 사용함으로써 Great Belt교, Stonecutter교, Messina교 등과 같이 혁신적인 단면을 채택한 교량에 비하여 상대적으로 기술적 가치를 인정받지 못하고 있다. 따라서 새로운 내풍 단면의 개발은 교량 설계를 위한 실용적인 측면에서 매우 중요하다. 본 연구에서는 경제적이고 내풍안정성이 우수한 도전적인 현수교 단면을 개발하는데 목적을 두고 있다. 이를 위하여 먼저 교량 계획 단계에 필요한 자료를 제공하기 위하여 기존 강박스 현수교의 제원을 수집하고 그 특성을 분석하여 각종 구조 변수들이 내풍안정성에 미치는 상대적인 영향을 평가하고, 근사적으로 고유진동수를 추정할 수 있는 추정식을 제시하였다. 그 다음으로 초장대 현수교 단면을 개발하기 위하여 다양한 풍동실험을 수행하고 가능한 단면 형상을 제시하였다.